There is only 3 AutoCAD coordinates system you should know. Absolute coordinates, Relative coordinates and Polar coordinates.

**Absolute Coordinates**

All input points specify in your drawing using standard Cartesian coordinates x and y. Using absolute coordinate, points entered by typing x,y [Enter]

Relative Coordinates

After first points entered, your next points can be entered by specifying the next coordinate compare/relative from the first points. The relative coordinate started with symbol “@” tell AutoCAD it was a relative coordinates. Using relative coordinate, points entered by typing @x,y [Enter]

**Polar Coordinates**

Polar coordinates used when you need to draw the next points at specify angle. Polar coordinates system in AutoCAD specifies distance length at which angle. Using polar coordinate, points entered by typing @distance<angle [Enter]

Example of AutoCAD coordinates usage;

Drawing 2 lines as figure shown with;

**Absolute coordinates**

Enter LINE command: L [Enter]

Start line at point A: 0,0 [Enter]

End first line at point B: 2,2 [Enter]

End of second line at point C: 2,3 [Enter]

**Relative coordinates**

Enter LINE command: L [Enter]

Start line at point A: 0,0 [Enter]

End first line at point B: @2,2 [Enter]

End of second line at point C: @0,1 [Enter]

**Polar coordinates**

Enter LINE command: L [Enter]

Start line at point A: 0,0 [Enter]

End first line at point B: @2.828<45 [Enter]

End of second line at point C: @1<90 [Enter]